Download Comodo Firewall
Comodo Firewall is one of the most effective protection for your computer. It not only detects, but prevents a virus to act and destroy or infect important data or information into your system. The firewall first scans any file you attempt to open and monitors any suspicious behavior of the same. A great feature included in this firewall is the option of creating a "virtual space" where the dangerous files can be analyzed and fixed by the program without your real system getting damaged by dangerous viruses.
Its easy to use for unexperienced users since the interface is really organized and simple.